Charlie- Area: yuppers. I have Def Tech BP-30's for my surrounds. 4 6.5" drivers per. Their -3 dB point is probably 30 Hz or so.
BoB- Me? Building a speaker? That's a good one...
I'm looking at rears. Have it narrowed to B&W DM601 S3, Acoustic Energy Aesprit 300C, Paradigm Mini Monitors, and a few others. They all have 6.5" mids/woofers that at least I'm trying to match the size with the BP-30's. (All 1" tweeters too.)
(Won't go with Def Tech, because I've seen some nasty freq response curves of the Pro Monitor 100/200 and Studio Monitor 350/450 with a hump at ~13.25 kHz.)